A capacitive sensor senses a capacitance change that occurs when a body or a particular object approaches. A traditional method for detecting the capacitance change induces charge into the capacitive sensor by using a large capacity capacitor and measures a time when a charging voltage of the capacitor becomes a reference voltage. The method as stated above needs be charged and discharged a number of times because an amount of induced charge into the capacitive sensor is small, and the capacitive sensor is affected by surrounding environment or noise.
Another traditional method for detecting a capacitance change induces charge into a capacitive sensor by a set number of times and measures a voltage change according to discharging time of induced charge. The method as stated above measure a discharging voltage of specific point of time, so that the discharging voltage is affected by surrounding environment or noise. As a result, the traditional methods have a possibility to misdetection of the capacitance change of the capacitive sensor.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.